Low noise echo ranging system based switching network

Abstract

The invention provides a low-noise echo ranging system based on switch network. It is formed frmo low-noise ultrasonic transmitting circuit consisting of a set of energy balls, low-noise receiving circuit, feedback control circuit and probe, and the circuit structure of ultrasonic wave can be desgined into a time-shared, zoned and frequency-divided switch-isolated network circuit structure. As compared with existent technology, it can completely cut off the electric noise influence of transmitting circuit and other electric interference signal on receiving circuit, can extend measurement range of low-noise echo ranging system; its continuously adjustable feedback energy storaeg unit 'energy regulating ball' has the characteristics of ultrasonic energy storage and high-pressure excitation so as to implement automatic gain control of probeg continuous energy and raise the signal-noise ratio of system.

Description

technical field [0001] The invention belongs to the technical field of electronic measurement, and in particular provides a low-noise echo ranging system based on a switch network, which is suitable for large-range low-noise ultrasonic ranging. Background technique [0002] Existing ultrasonic level measurement generally uses standard chips or programmable chips as controllers, such as Chinese patents 02270240.7 "An Ultrasonic Distance Measuring Device" and 93211624.8 "An Ultrasonic Distance Measuring Device". The ultrasonic transducer is excited to generate an ultrasonic transmission signal, and the signal is then amplified, filtered, detected and other ultrasonic signal processing to complete a ranging task. The standard chip is a standard integrated circuit, which can generate a series of rectangular pulse waves. The pulse waves are amplified by a transformer, and output high voltage on the secondary side to drive the probe to work. The echo of the ultrasonic signal is r...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is: with the increase of excitation energy, the voltage noise at both ends of the transformer, the spike noise of the excitation voltage instantaneous start also increases, and the signal-to-noise ratio of the probe in the echo target area decreases.

[0007] Chinese patent 02248586.4 "Ultrasonic Range Finder" presents the idea of ​​voltage compensation based on the strength of the detection signal, but this compensation is directly aimed at the amplifier circuit, so the stronger the compensated voltage, the greater the noise

Its design idea (1) uses capacitor as the energy storage element to charge and discharge the probe, but the energy of the energy storage element itself is not continuously adjustable; (2) the setting switch is mainly used for the rapid discharge of the inductance element, To prevent the tail wave of the probe from being too long, the isolation effect of the switch itself is not reflected

Images